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Optical CCD spectra are used to determine the Fe abundances at several positions inside seven bright Galactic HII regions. The observed [FeIII] line ratios are compared with the predictions of different sets of collision strengths and…

Astrophysics · Physics 2009-11-07 M. Rodriguez

We report a detection of an absorption line at ~44.8 {\AA} in a > 500 ks Chandra HRC-S/LETG X-ray grating spectrum of the blazar H 2356-309. This line can be identified as intervening CV-K{\alpha} absorption, at z\approx0.112, produced by a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Luca Zappacosta , Fabrizio Nicastro , Yair Krongold , Roberto Maiolino

We use archival UV absorption-line data from HST/STIS to statistically analyse the absorption characteristics of the high-velocity clouds (HVCs) in the Galactic halo towards more than 40 extragalactic background sources. We determine…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Peter Herenz , Philipp Richter , Jane C. Charlton , Joseph R. Masiero

We present a detection of a broad Ly-alpha absorber (BLA) with a matching O VI line in the nearby universe. The BLA is detected at z = 0.01028 in the high S/N spectrum of Mrk 290 obtained using the Cosmic Origins Spectrograph. The Ly-alpha…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-19 Anand Narayanan , Bart P. Wakker , Blair D. Savage , Brian A. Keeney , J. Michael Shull , John T. Stocke , Kenneth R. Sembach

We present an ultraviolet quasar absorption line analysis of metal lines associated with three strong intervening H I absorbers (with $N$(H I) $>$ 10$^{16.5}$ cm$^{-2}$) detected in the outskirts of Sunyaev-Zel'dovich (SZ) effect-selected…

Astrophysics of Galaxies · Physics 2019-08-07 Jayadev Pradeep , Anand Narayanan , Sowgat Muzahid , Daisuke Nagai , Jane C. Charlton , Raghunathan Srianand

We present detailed photoionization models of well aligned optically thin C III absorption components at $2.1 < z < 3.4$. Using our models we estimate density ($n_{\rm \tiny H}$), metallicity ($[C/H]$), total hydrogen column density and…

Astrophysics of Galaxies · Physics 2019-01-23 Abhisek Mohapatra , R. Srianand , Vikram Khaire , Ananta C. Pradhan

We observed the Seyfert I active galaxy/broad line radio galaxy 3C120 with the Chandra high energy transmission gratings and present an analysis of the soft X-ray spectrum. We identify the strongest absorption feature (detected at >99.9%…

Astrophysics · Physics 2009-11-10 B. McKernan , T. Yaqoob , R. Mushotzky , I. M. George , T. J. Turner

We are presenting here a follow-up study of the molecular gas and dust in the environs of the star forming region NGC 3503. This study aims at dealing with the interaction of NGC 3503 with its parental molecular cloud, and also with the…

Astrophysics of Galaxies · Physics 2014-05-08 N. U. Duronea , J. Vasquez , G. A. Romero , C. E. Cappa , R. Barbá , L. Bronfman

We report observations of the CO J=7->6 transition toward the starburst nucleus of NGC 253. This is the highest-excitation CO measurement in this source to date, and allows an estimate of the molecular gas excitation conditions. Comparison…

We analyze the cool gas in and around 14 nearby galaxies (at $z$$<$0.1) mapped with the SDSS-IV MaNGA survey by measuring absorption lines produced by gas in spectra of background quasars/AGN at impact parameters of 0-25 effective radii…

Associated absorption lines (AALs) in quasar spectra are valuable probes of the gas kinematics and physical conditions in quasar environments. The host galaxies are by definition in an active evolution stage that might involve large-scale…

Astrophysics of Galaxies · Physics 2018-09-17 Chen Chen , Fred Hamann , Leah Simon , Thomas Barlow

Observations of the "Warm Ionized Medium" (or, equivalently, the "Diffuse Ionized Gas") of the local ISM, the Perseus arm in the Milky Way, and also in several other galaxies show strong [NII]6563 (~H-alpha in some cases) and…

Astrophysics · Physics 2009-10-31 John S. Mathis

We detect seven distinct absorbing systems in the high-resolution X-ray spectrum of the Seyfert 1 galaxy IC 4329A, taken with XMM-Newton. Firstly we detect absorption due to cold gas in our own Galaxy and warm gas in the Galactic halo or…

To determine the properties of the ionized gas at the edge of the CMZ near Sgr E we observed a small portion of the edge of the CMZ near Sgr E with spectrally resolved [C II] 158 micron and [N II] 205 micron fine structure lines at six…

Astrophysics of Galaxies · Physics 2015-06-23 W. D. Langer , P. F. Goldsmith , J. L. Pineda , T. Velusamy , M. A. Requena-Torres , H. Wiesemeyer

As one of the most luminous radio-loud quasars showing intrinsic ultraviolet (UV) and X-ray absorption, 3C 351 provides a laboratory for studying the kinematics and physical conditions of such ionized absorbers. We present an analysis of…

Astrophysics · Physics 2009-11-07 Q. Yuan , R. F. Green , M. Brotherton , T. M. Tripp , M. E. Kaiser , G. A. Kriss

We present evidence for X-ray line emitting and absorbing gas in the nucleus of the Broad-Line Radio Galaxy (BLRG), 3C 445. A 200ks Chandra LETG observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft…

High Energy Astrophysical Phenomena · Physics 2015-05-20 J. N. Reeves , J. Gofford , V. Braito , R. Sambruna

We report on the detection of Ne VIII in an intervening multiphase absorption line system at z=0.32566 in the FUSE spectrum of the quasar 3C 263. The Ne VIII 770 A line detection has a 3.9 sigma significance. At the same velocity we also…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Anand Narayanan , Bart P. Wakker , Blair D. Savage

We searched for 21-cm absorption associated with the z_abs = 1.3647 absorption system toward PKS 0237-233 using the GMRT. A high quality UVES spectrum shows that C I and C I* are detected at this redshift together with C II*, Mg I, Mg II,…

Astrophysics · Physics 2008-11-26 Raghunathan Srianand , Neeraj Gupta , Patrick Petitjean

Context. The study of abundances in the nucleus of active galaxies allows us to investigate the evolution of abundance by comparing local and higher redshift galaxies. However, the methods used so far have substantial drawbacks or rather…

We combine CaII/NaI absorption and HI 21 cm emission line measurements to analyse the metal abundances, the distribution, the small-scale structure, and the physical conditions of intermediate- and high-velocity gas in the Galactic halo.

Astrophysics · Physics 2009-11-11 Nadya Ben Bekhti , Philipp Richter , Tobias Westmeier